A typical known stator for a brushless motor comprises a stator core which comprises an annular yoke and a plurality of teeth radially extending from the yoke. Traditionally the stator core is formed by stacking a plurality of stator laminations together and each lamination is a monolithic piece with a closing structure. During production, the stator laminations are stacked together to form the stator core firstly, and then stator windings are wound on the teeth of the stator core. It is not convenient to wind windings on a closing structure, so the winding efficiency is low and sometimes the number of turns of the winding is limited.
U.S. Pat. No. 6,919,665 discloses a stator core which is formed by laminated strip-shaped straight cores. The straight core includes a plurality of yokes, a plurality of teeth extending from the yokes, and bent portions between adjacent yokes. The bent portions are provided with V-shaped notches. A pair of arc shaped fitting portions are formed on a pair of surfaces defining the V-shaped notches so as to prevent relative movement between adjacent yokes. The straight cores are formed into an annular configuration by bending the bent portions in a direction so as to close the V-shaped notches. In this patent the above mentioned problem is able to be solved. However, as the arc shaped fitting portions can only prevent relative axial movement between the adjacent yokes, after the external force for bending a bent portion is withdrawn a rebound between the adjacent yokes may occur, which will result in undesired relative circumferential movement between the adjacent yokes.
Hence, there is a desire to provide a new stator core which addresses this problem.